Solder Oven?

[Gardenerbill]

I am investigating the 801st M.T. Coy who were based in Salonika, while transcribing their war diary I came across the following entry.

Googling Solder Oven I came up with this in wiki:

Reflow soldering is a process in which a solder paste (a sticky mixture of powdered solder and flux) is used to temporarily attach one or several electrical components to their contact pads, after which the entire assembly is subjected to controlled heat, which melts the solder, permanently connecting the joint.

So the question is, was this technique used as early as 1918? And if not then what could a Solder Oven be?

[keithfazzani]

Solder was also used as a sort of "welding" process. I came across it in a previous career where there was a factory manufacturing copper pressure vessels, these had gunmetal rings as the flange soldered on with a tin paste of some sort. I have no idea of the technicalities but I have a memory of the paste being heated in a small oven prior to it being wiped on. It was then further melted into the groove that formed the join using a brazing tool. Indeed I think the process was called brazing. I am sure someone more technical than me will come along and explain further.

[johnboy]

I did the same 'google' and came up with numerous descriptions that match yours. I did not mention them as I assumed that these were not what was referred to,

I imagined something on a grand scale as it said 8 men were to work on it!

[rolt968]

Many, many, many years ago, I think solder was used to attempt to fill small holes in cast iron baths. They can't have tried the same thing with an oven, surely.

Roger.

[asanewt]

The references to a number of vehicles make me wonder if immersion soldering of radiators is involved and whether PBs are local labour taken on to build the brick kiln/ovens.

[johnboy]

Isn't copper used for repairing radiators? Thus requiring brazing?

[David B]

My guess is the same as JulesW. Radiators in those days were held together/sealed by soldered joints and the process probably involved dipping the repaired radiator in a solder over, after making sure the parts to be joined were properly

cleaned and flux added to enable the solder to seal the brass radiator.

[asanewt]

Copper cores soldered to brass top/bottom tanks. Copper is soldered usually as in domestic plumbing along with brass.

Brazing is preferred for stronger bonds and/or higher operating temperatures than melting point of solders.

Fusion welding for stronger and yet higher temp.

[johnboy]

So, would solder be used to repair vehicle radiators which operate under pressure?

[asanewt]

Yes, until Plastic and neoprene seals raised their beautiful heads.

Just for info. in most cases the cooling systems of that date were not pressurised. As system pressures increased over time soldering was perfectly adequate and still is in sealed heating systems. If you have combi boiler check the system pressure gauge.

The big change in vehicle cooling system pressure was motivated in the main by the need to negotiate the high passes of the Andes by those crossing from the wrong side in the World Cup Rally ending in Mexico City 1970??

[David B]

Yes, from memory the solder joint was fairly wide, and the header tank slid over the framework of the radiator to provide strength, certainly far enough to withstand the pressure generated in a radiator. In my early days

as a technician in the post office we learned many of these techniques such as lead wiping (joining lead covered cables) and how to solder properly. Of course much of this has passed into antiquity being surpassed

by more modern use of plastics.

[asanewt]

Ha! David, I can remember quite far back but 1918! Respect

[David B]

This type of radiator construction was still used as late at post ww2, first car I drove and partially serviced was a 1925 Chev. (it had a fantastically accurate fuel gauge - a carpenters rule in the tank and 1 inch equalled 1 gallon)

[Gardenerbill]

Thank you everyone, great discussion, repair and even fabrication of vehicle radiators seems to be the most likely use.

On the subject of the 8 P.B. men, P.B. was a classification of men no longer fit for front line duty. There may have been 8 of them brought in to build the oven which I assume would have been quite large if it had to accommodate lorry radiators.

[T8HANTS]

I had to rebuild a 1940's Morris C9/B rad' out of the remains of two, and that was all soldered.

However the solder oven may refer to the need to keep the soldering irons up to temperature, as I remember we had three on the go at once, warmed in a gas heated box. If you were operating in a workshop a method of keeping the irons at the right temperature for periods of time would be vital. So I suspect it could be some form of solid fuel oven for the soldering irons.

G

[centurion]

I had to rebuild a 1940's Morris C9/B rad' out of the remains of two, and that was all soldered.

However the solder oven may refer to the need to keep the soldering irons up to temperature, as I remember we had three on the go at once, warmed in a gas heated box. If you were operating in a workshop a method of keeping the irons at the right temperature for periods of time would be vital. So I suspect it could be some form of solid fuel oven for the soldering irons.

G

I have been out all day or might have put my oar in earlier but T8 is absolutely right. Electric soldering irons were relatively rare in the period and electricity itself might have not been available in many locations. I was taught to solder tin-plate at school in the late 50s using big heavy soldering irons (built that way to retain the heat much as old fashioned clothes pressing irons were) the soldering irons were kept hot in soldering iron ovens - in our case gas fired. The Master in Charge had once kept the vehicles of the 8th Army in Italy on the road.

[asanewt]

"The Master in Charge had once kept the vehicles of the 8th Army in Italy on the road."

Ha! Ours had "lapped six inch nails in with tapioca" in the absence of spare valves with the Desert Rats

Back to topic, batch soldering would also use hot plates as heat sinks.

[Radlad]

Soldering ovens come in many shapes and sizes, small ones are used to heat irons, larger ones can be used for heating parts right through, as opposed to the local heat from an iron. They can also be used to heat lead pots to be carried to the job where the solder would be ladled on to the job ( as in vehicle bodywork). Another use for such an oven would be tempering or normalising metal after blacksmithing work.

I served 2 years of my apprenticeship learning soldering and leadwork, now, most of the practices I learned are illegal. They survived from Roman times until the 1980's.

For 8 men to be involved, I would expect the oven to be a reasonable size for light engineering work

[johnboy]

What is a reasonable size and what would it be made of and what would fuel it?

[Radlad]

Imagine a blacksmiths hearth , but with a box like cover. The sides of the cover have portals and rests built into that soldering irons could be poked into and the handles rested out of the heat. These portals could be closed off to keep heat in. The largest I have seen was in an old tin works in Rochdale many years ago and was out of use then . The fire space was about 7ft long , 2ft wide and 2ft high. Coal fired with a door at each end for stoking, raking and introducing large parts for heat treatment. Weight must have been about 2 tons guestimate) . It must have been hard work to operate as the flame had to be kept 'clean' , a 'dirty' flame would just soot up anything being heated.

Smaller ones with one or two portals were common in schools but had gone out of use in industry by my time. They were usually fired with gas by an aerated burner and had a suitably sized cast iron cover to keep the heat round the irons. a small gas fired one would occupy a space of less than a foot cubed.

[centurion]

Imagine a blacksmiths hearth , but with a box like cover. The sides of the cover have portals and rests built into that soldering irons could be poked into and the handles rested out of the heat. These portals could be closed off to keep heat in. The largest I have seen was in an old tin works in Rochdale many years ago and was out of use then . The fire space was about 7ft long , 2ft wide and 2ft high. Coal fired with a door at each end for stoking, raking and introducing large parts for heat treatment. Weight must have been about 2 tons guestimate) . It must have been hard work to operate as the flame had to be kept 'clean' , a 'dirty' flame would just soot up anything being heated.

Smaller ones with one or two portals were common in schools but had gone out of use in industry by my time. They were usually fired with gas by an aerated burner and had a suitably sized cast iron cover to keep the heat round the irons. a small gas fired one would occupy a space of less than a foot cubed.

More usually coke rather than coal fired in order to avoid the soot etc refered to.

[johnboy]

Could it be fuelled with charcoal?

[centurion]

Could it be fuelled with charcoal?

Yes but this would be more expensive. Coke generally replaced charcoal by the end of the 18th Century in British metal working as

• It was becoming too expensive (the woods/charcoal burners couldn't meet the demands of the industrial revolution)
• There were limitations on the maximum size of oven/furnace you could use charcoal in (it tends to crush easily)

I've a textbook on this somewhere but I probably haven't opened it for about 50 years!

[johnboy]

The reason for the question relates to another thread about MT Company in Salonika where the war diary talks of daily runs for charcoal.

[centurion]

The reason for the question relates to another thread about MT Company in Salonika where the war diary talks of daily runs for charcoal.

I suspect that outside the main cities in all of Greece and Macedonia coke was not common as the region was not much industrialised but charcoal would still be a widely used fuel for cooking. Before the industrial revolution charcoal was the usual fuel for forges, furnaces, ovens etc used .in industrial processes as it gave off great heat but was relatively clean burning. Coal was rarely used for this as it produces soot and sulphur. Peasant/artisan level metal working concerns in parts of Africa were still using charcoal in small scale enterprises well into the 20th century (and possibly still are)